Additional Study Information: This research study is being done to test the safety of an investigational treatment called LOXO-305. LOXO-305 is an investigational drug that may treat certain cancers like leukemias and lymphomas, including the one you have been diagnosed with. These cancers are dependent on or addicted to a protein made by the cancers called BTK. LOXO-305 is a BTK inhibitor. It is designed to block both normal and mutated forms of BTK in these cancers, including cancers against which available BTK inhibitors (e.g. ibrutinib, acalabrutinib) have stopped working. The purpose of this research study includes the following: to determine whether LOXO-305 is safe; to identify the dose of LOXO-305 that should be used in future studies; to identify the highest tolerable dose of LOXO-305; to evaluate how the body absorbs and processes different doses of LOXO-305 by measuring the levels of LOXO-305 in the blood at different times- this is called pharmacokinetics (PK) testing; to determine how well your cancer responds to treatment with LOXO-305; and to determine how long any benefits from treatment with LOXO-305 last.